Laguna Alta is a turnkey BOOT (Build, Own, Operate and Transfer) project involving the construction of a 76 Mld potable water treatment plant for Aguas de Panama. The construction included water sampling and analysis, process design, hydraulic design, civil, mechanical and electrical design, procurement of all materials, construction and initialising the operation of the plant.
Raw water is obtained from Lake Gatun, which is the head water lake for the Panama Canal.
Abstracted water is pumped using vertical turbine pumps, through roughing filters adjacent to the lake before being forwarded by high lift pumps through an 11 kilometre, 900mm diameter ductile iron pipe to the treatment plant.
The treatment consists of triple drop aeration, rapid mixing, flocculation, coagulation and clarification by the DAF (Dissolved Air Floatation) process prior to rapid gravity filtration and disinfection. This is carried out in a contact tank before storage in a one million US gallon (3,800m³) on-site reservoir.
The potable water then gravitates approximately 10 kilometres through a 700mm diameter ductile iron treated water main. Delivery is direct into the Client’s own existing distribution system.
Due to the high static heads involved in supplying raw water to the treatment plant, a scheme specifically designed for cleaning and recovery of the filter backwash water has been installed. This has resulted in plant losses being exceptionally low.
The contract also includes a pipeline consisting of five kilometres of 600mm diameter ductile iron pipe which increases the Client’s distribution system. It also includes two inline booster pumping stations which are used by the client for the operation and maintenance of this BOOT project.
Cascal, part of the Biwater Group, has complete responsibility for ensuring that the guaranteed volumes of potable water are available to the served population of approximately 300,000 people.
The water quality has to meet contractual standards at all times for the duration of the contract. In order to achieve this Cascal has invested in a state of the art treatment processes using in-house proven technology. Training of local operational personnel has been given a high priority in order that the plant consistently produces potable water to World Health Organisation (WHO) standards.
Main Items of Equipment
- Vertical Turbine Pumps
- Horizontal Split Casing Pumps
- Roughing Filter Underdrains
- Flash Mixing Equipment
- Flocculators
- Dissolved Air Floatation Tanks (DAF) and Scrapers
- Rapid Gravity Filter Underdrains
- Backwash Water Recovery Equipment